

MIOCENE PORPOISES — KELLOGG 137 



Measurements of mandibles (in millimeters) 



Right Left 

 Length of mandible (as preserved) from condyle to 



anterior end 318.+ 321. + 



Length of symphysis (as preserved) 39.+ 43.+ 



Vertical diameter of mandible at hindmost alveola 38. 5 38. 5 

 Transverse diameter of mandibles at posterior end 



of symphysis 40. ± 

 Vertical diameter of mandible at level of posterior 



end of symphysis 25. 25. 

 Vertical diameter of mandible through coronoid 



process 73.+ 83.0 



11 posterior teeth located in an interval of 113. 110. 



12 posterior teeth located in an interval of 131. 121. 

 Anteroposterior diameter of largest alveola 8. 8. 

 Transverse diameter of largest alveola 7. 7. 

 Distance from posterior end of symphysis to hind- 

 most alveola 115.0 110.0 



Distance from apex of coronoid process to hindmost 



alveola 139. 

 Distance that orifice of dental canal is located behind 



hindmost alveola 35. ± 35. ± 

 Distance from posterior end of symphysis to pos- 

 terior surface of condyle 282. 283. 

 Height of condyle 33. 29. ± 

 Transverse diameter of condyle 16. 

 Least distance between alveolae in tooth rows 2. 2. 



TEETH 



The two teeth in the left mandible (the ninth and tenth, counting 

 forward from the hindmost) have the apical portions of the crowns 

 curved inward. The ninth tooth in the left mandible (pi. 16, fig. 9) 

 has the basal 2 to 3 mm. of the enamel on the circumference of the 

 crown ornamented with low tonguelike projections extending more or 

 less vertically from the basal border, although this sculpturing is more 

 pronounced on the internal than on the other faces. The anterior 

 and posterior edges of the internal face are delimited by a low carina 

 that extends to or nearly to the apex of the crown. 



On the 10th tooth the anterior vertical carina is definitely on the 

 anterior face of the crown, while the posterior carina delimits the 

 internal face. The shallow grooves between the tonguelike projec- 

 tions from the basal circumference extend farther toward the apex 

 of the crown on the internal face (pi. 16, fig. 10) than on the ninth 

 tooth. 



On both of these teeth the enamel on the apical portion of the 

 crown is relativelj^ smooth. The measurements of the ninth tooth 

 in the left mandible are as follows: Height of crown, 10.5 mm. ; antero- 



